//
// Handler.h
//
// Library: JSON
// Package: JSON
// Module:  Handler
//
// Definition of the Handler class.
//
// Copyright (c) 2012, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier:	BSL-1.0
//


#ifndef JSON_Handler_INCLUDED
#define JSON_Handler_INCLUDED


#include "Poco/Dynamic/Struct.h"
#include "Poco/Dynamic/Var.h"
#include "Poco/JSON/JSON.h"
#include "Poco/SharedPtr.h"


namespace Poco
{
namespace JSON
{


    class JSON_API Handler
    /// Interface for handling parsing events generated by the JSON Parser.
    ///
    /// An application can implement a subclass of Handler to implement
    /// callback-based parsing of a JSON document, similar to how a SAX
    /// parser would handle XML.
    {
    public:
        typedef SharedPtr<Handler> Ptr;

        Handler();
        /// Creates an empty Handler.

        virtual ~Handler();
        /// Destroys the Handler.

        virtual void reset() = 0;
        /// Resets the handler state.

        virtual void startObject() = 0;
        /// The parser has read a {, meaning a new object will be read.

        virtual void endObject() = 0;
        /// The parser has read a }, meaning the object is read.

        virtual void startArray() = 0;
        /// The parser has read a [, meaning a new array will be read.

        virtual void endArray() = 0;
        /// The parser has read a ], meaning the array is read.

        virtual void key(const std::string & k) = 0;
        /// A key of an object is read.

        virtual void null() = 0;
        /// A null value is read.

        virtual void value(int v) = 0;
        /// An integer value is read.

        virtual void value(unsigned v) = 0;
        /// An unsigned value is read. This will only be triggered if the
        /// value cannot fit into a signed int.

        virtual void value(Int64 v) = 0;
        /// A 64-bit integer value is read.

        virtual void value(UInt64 v) = 0;
        /// An unsigned 64-bit integer value is read. This will only be
        /// triggered if the value cannot fit into a signed 64-bit integer.

        virtual void value(const std::string & value) = 0;
        /// A string value is read.

        virtual void value(double d) = 0;
        /// A double value is read.

        virtual void value(bool b) = 0;
        /// A boolean value is read.

        virtual Poco::Dynamic::Var asVar() const;
        /// Returns the result of the parser (an object, array or string),
        /// empty Var if there is no result.

        virtual Poco::DynamicStruct asStruct() const;
        /// Returns the result of the parser (an object, array or string),
        /// empty Var if there is no result.
    };


}
} // namespace Poco::JSON


#endif // JSON_Handler_INCLUDED
